1. Field of the Invention
The invention relates generally to the field of photography, and in particular to cameras.
2. Description of the Prior Art
Typically in a number of relatively inexpensive 35 mm still-picture cameras, a film take-up drum or spool is manually rotated after each exposure to advance successive frames (imaging areas) of the filmstrip from a light-tight cartridge across the focal plane of a taking lens and onto the take-up drum. Each time the take-up drum is manually rotated, an unexposed frame of the filmstrip is positioned in the focal plane of the taking lens and an exposed frame is wound onto the take-up drum. At the same time, a metering sprocket in engagement with successive perforations in the filmstrip is rotated a single 360.degree. revolution by advancement of the filmstrip substantially a frame increment. When the metering sprocket completes its 360.degree. revolution, the sprocket is temporarily locked in place. Preferably, the take-up drum is similarly locked. After each exposure, the metering sprocket and the take-up drum are unlocked to allow film movement to be resumed in order to wind the exposed frame onto the take-up drum and to position another frame in the focal plane of the taking lens.
To rewind the filmstrip from the take-up drum back into the light-tight cartridge once all of the available frames have been exposed, a rewind knob in engagement with the film spool inside the cartridge is manually rotated to, in turn, rotate the film spool to take-up the filmstrip. During film rewind, the metering sprocket is rotated by the filmstrip in a direction opposite to the one it was rotated when the filmstrip was wound onto the take-up drum, and the locking mechanism for locking the sprocket and the drum in place is disabled.
Often, an operating element of the camera is actuated to perform a function, such as cocking a shutter or cocking a high energy member, when the metering sprocket is rotated in the direction attendant with film movement onto the take-up drum. Conversely, the operating element is not actuated for such purpose when the metering sprocket is rotated in the direction attendant with film movement back into the light-tight cartridge. Generally speaking, the prior art designs linking the operating element and the metering sprocket stand in need of simplification.